In transporting cargo of various types, shipping containers of wood, fiber board, or the like are used to hold and protect the cargo. One common type of container is a box having rigid sidewalls, typically constructed of wood, resting upon a pallet and including a cover or lid to complete the enclosure. Once the cargo has reached its destination, the box is dismantled and discarded.
Due to the cost of construction of such rigid containers, collapsible boxes have been produced so that when such a box is not in use it may be collapsed for storage or for return to the point of origination of the cargo for re-use.
Such prior collapsible boxes have taken a number of forms. Some are held together by fairly elaborate arrangements of encircling wires and/or metal bands. These types of collapsible boxes present difficulties in re-assembly and disassembly.
Another common type of shipping box includes four sides, which are substantially vertical when the box is in use, each side having several vertical slats held together by a number of horizontal cleats. The sidewalls either rest upon or are secured to a base or pallet, and a suitable cover or lid may be additionally provided.
In a collapsible box of this type, in one prior construction, the sidewalls are held together at the corners by interlooped wire elements, the ends of which are permanently secured between adjacent cleats and slats. Such a sidewall structure relies for its rigidity upon a rectangular border on the pallet base upon which the walls are positioned. When the four walls are removed from the base, the interlooped connecting elements at the corner are sufficiently loose to permit the sidewalls to collapse into a flattened condition. In the collapsed condition of this type of box, the sidewalls are not disconnected from one another since the interlooped wire elements are permanently secured to the sidewalls. Unfortunately, due to some looseness in the connecting elements, which is necessary to allow the box to collapse, this box is not very sturdy after more than one use, particularly when shipping contents for which no lid is required.
In another collapsible box having sidewalls of the same general type as that described above, holes are drilled through the cleats which are adjacent one another at each of the corners of the box. Then, to releasably secure the sidewalls together, a single wire loop element is passed through the bores through the cleats, with the ends of the wire element then twisted together. This type of attachment of the collapsible box sidewalls, while permitting disassembly of the walls from one another, also fails to provide a particularly rigid connection for the sidewalls.
Long U.S. Pat. No. 4,650,084 discloses a collapsible box with sidewalls that may be secured together in a manner that they may be readily disassembled from one another and yet, when assembled, provide a relatively rigid and sturdy structure. This is accomplished via loop elements with tapered nails which permanently connect to the cleats and tie means for releasably securing adjoining loop elements at the corners of the box.
The Long invention facilitates assembly and disassembly of the walls of a collapsible box. Nevertheless, the assembly and disassembly of this particular box, and others, requires excessive labor and time because it is still necessary to tie and untie the cleats at the corners every time the box is assembled or disassembled, respectively.
It is an objective of this invention to further facilitate the assembly and disassembly of a collapsible box used in shipping cargo.
It is another objective of this invention to reduce the labor required to assemble and disassemble a collapsible box.
It is still another objective of the invention to maintain a high degree of rigidity for a collapsible box that is easy to assemble and disassemble.
The above-stated objectives are achieved by a collapsible box designed to allow the sidewalls to remain interconnected when fully collapsed and not in use but with the connecting elements sufficiently tight to maintain structural rigidity over a number of uses. Because this box is fully collapsible with the walls remaining interconnected, this box eliminates the need to interconnect and disconnect the cleats at the corners of the box every time the box is assembled or disassembled. Nevertheless, because this invention employs the connecting elements and the tie means of the above-identified Long patent, the rigidity of the box can be assured by periodically retightening the tie means between each set of interconnecting connector elements.
This invention contemplates the use of cleats having ends with reverse miters at the corners of the box. With reverse miter cleats located at least at two diagonally opposing corners of a collapsible box, the interconnected walls may be fully collapsed together during periods of non-use, with the connecting elements remaining relatively tight to assure structural rigidity for the box.
According to a preferred embodiment of the invention, a fully collapsible box comprises four sidewalls of vertical slats secured together by horizontal cleats which are interconnected to the cleats of adjacent sidewalls, at the corners, by interconnecting wire loops, wherein the loops remain connected to the cleats and the adjoining loops are tied together by tie means of the type disclosed in the above-identified Long patent. For at least two diagonally opposing corners of the box, the cleats have reverse miterd corners to allow the box to be collapsibly hinged while all four sidewalls remain tightly interconnected. The reverse miters allow the box to be relatively easily collapsed without significantly affecting the tightness of the interconnected loops. Periodically, the connected loops may be retightened, if necessary.
According to one alternative embodiment, a single continuous wire loop extends all the way around the box and is held in place by staples. Use of a single loop eliminates any loosening of the interconnections at the corners which eventually form the two ends of the collapsed box, because the tension generated at these corners is offset by the slack generated in the wire at the other two diagonally opposing corners.
These and other features of this invention will be more readily understood in view of the following detailed description of the drawings.